★★★★★
Cx5 standard servicing, changing of battery and transmission oil. Thank you Jin for the great customer service.
Joe C.
The second, smaller battery that backs up your car's electronics. We test it, fit the correct battery, and code it where your car needs it. Dealer-level know-how, and honest with your wallet.
Seeing an auxiliary battery malfunction message, start-stop that has stopped working, or random electrical faults? We test the auxiliary battery and the charging system first, so you only replace what actually needs replacing, then code the new battery where your car needs it.
Why Singapore drivers trust 1 Car Service with their auxiliary battery
An auxiliary battery warning is not always the auxiliary battery. We test both batteries and the charging system first, and only replace what the tests show you need.
Mercedes, BMW, Audi, VW and Volvo track their batteries through a management system. Where the car needs it, we register the new battery with dealer-level tools (XENTRY, ISTA, ODIS, VIDA) so the charging system treats it as new.
Most auxiliary battery replacements are done at our Sin Ming workshop while you wait. Honest pricing quoted before we start, and you can spread the cost with Atome, Grab or Shopee.
An auxiliary battery malfunction usually means your car's second, smaller battery, the one that backs up the electronics, start-stop and safety systems, is flagged as weak or failing. It is most common on Mercedes-Benz, which shows an 'Auxiliary Battery Malfunction' message, and certain Volvo, BMW, Audi and Porsche models carry a backup or support battery too, depending on the variant. It is usually a small AGM battery that lasts about four to six years, and often closer to three to four in Singapore's heat. Resetting the message does not fix or diagnose it, so the real answer is to test first and confirm whether the fault is the auxiliary battery, the main battery or the charging system. At 1 Car Service in Singapore, we test the auxiliary battery and the charging system first, then fit and, where the car needs it, code the correct battery once we confirm it is the cause, using dealer-level tools (XENTRY, ISTA, ODIS, VIDA). Most replacements are done at our Sin Ming workshop while you wait.
I had my Volvo V40 serviced for a new auxiliary battery and timing belt change. Fast, efficient and to my satisfaction. The cost was very reasonable.
Was there to change the 12V battery (A200 sedan). JIn (service advisor) did not straight away conduct the change but instead checked to ensure that the existing battery is dying. After changing the 12V battery he also conducted a check on the auxiliary battery to ensure the condition is still good. Overall the change was fast and professional. Good job guys!
Honest and no-nonsense response from their technicians after they ran a check on my BMW 523i. No wild charges and unnecessary replacements. Battery replacement, brake fluid and engine oil change plus workmanship was below $830 after gst.
Attended by Jin and work started immediately. Changed the engine oil, transmission oil, brake fluid and battery. Transparent pricing. Done within 2 hours while i waited in their lounge. Jin even follow up asking car condition the next working day.
4.9★ from 1,767+ Google reviews
Cx5 standard servicing, changing of battery and transmission oil. Thank you Jin for the great customer service.
Joe C.
Transparent pricing , deliver as agree on the hybrid battery of my Cayenne , both DX & Jin did a great job. Highly Recommended,.
Chan M.
Toyota Voxy hybrid,Derek helped a lot.cleaned the hybrid battery filter for me. Great Good
Kevin L.
Serviced my Audi A3, was given a comprehensive checks, and the issues with the brakes and battery was detected and fixed promptly. Great service!
Charlie C.
Good and attentive service. Managed to recharge my Porsche Cayenne flat battery. Provided updates all the time. Would highly recommend!
Kelly N.
Jin provided a thorough service and alternator replacement for a Qashqai
Ryan G.
Good service and able to solve my car nissan xtrail issue of vibration cause by my rotor.
Edmund T.
As always Jin and the rest of the crew will be there to provide their best assistance and services. Thank you.
nabil Z.
Servicing was excellent especially Mr Jin who is incharged of my car who has been served proffessionally and im happy with his services.
Oyah S.
Excellent service by Jin and team, will be back again. They were fast and efficient in helping me sort out issues on my car.
Daniel S.
Serviced my GLC250 today. Steve was chill and straightforward. Waiting time was slightly longer but worth it. Car feels better after service. Would return.
Estella L.
Very helpful workshop and staff are very friendly highly recommended
chin C.
Cx5 standard servicing, changing of battery and transmission oil. Thank you Jin for the great customer service.
Joe C.
Transparent pricing , deliver as agree on the hybrid battery of my Cayenne , both DX & Jin did a great job. Highly Recommended,.
Chan M.
Toyota Voxy hybrid,Derek helped a lot.cleaned the hybrid battery filter for me. Great Good
Kevin L.
Serviced my Audi A3, was given a comprehensive checks, and the issues with the brakes and battery was detected and fixed promptly. Great service!
Charlie C.
Good and attentive service. Managed to recharge my Porsche Cayenne flat battery. Provided updates all the time. Would highly recommend!
Kelly N.
Jin provided a thorough service and alternator replacement for a Qashqai
Ryan G.
Good service and able to solve my car nissan xtrail issue of vibration cause by my rotor.
Edmund T.
As always Jin and the rest of the crew will be there to provide their best assistance and services. Thank you.
nabil Z.
Servicing was excellent especially Mr Jin who is incharged of my car who has been served proffessionally and im happy with his services.
Oyah S.
Excellent service by Jin and team, will be back again. They were fast and efficient in helping me sort out issues on my car.
Daniel S.
Serviced my GLC250 today. Steve was chill and straightforward. Waiting time was slightly longer but worth it. Car feels better after service. Would return.
Estella L.
Very helpful workshop and staff are very friendly highly recommended
chin C.
Battery, wipers, and AC filter replaced. The squeaky noise is gone and the AC smells fresh again. Great work, Steve!
Nick Luo W.
Brought my car for servicing, change of car battery and transmission oil. It was efficiently done and I could get back my car after 2 hours plus.
Law
Great service provided by Jin from 1 Car Service Workshop. Change of engine oil, gear oil, spark plugs and battery on my Audi A3. Tysm
Nigel Lee Shi Y.
Subaru battery replacement. Quick turnaround! Good job!
James L.
great service! Very prompt and explains well. Had a problem with my honda vezel battery, they did a thorough check to find the root cause. Thank you!
thashaini M.
I had my Volvo V40 serviced for a new auxiliary battery and timing belt change. Fast, efficient and to my satisfaction. The cost was very reasonable.
Niels de B.
Very good service! always do service & maintenance here for my Mercedes . Appreciate service advisor JIN. Tks!
Ming L.
ske2026g,car service,very good service and diagnosis was done well
Muhammad R.
sent my family car (Merc GLC Coupe 300 2022) in for 75k servicing at 1 Car servicing. brilliant job done by Jin, DX, Steve and the rest of the team!
Imran M.
Did a service for my cla180, Jin was very helpful and communication was efficient. Great experience overall.
Lou T.
Good, professional, fast servicing of my Mazda CX5. Highly recommend. Thumbs up to Steve for seeing the whole process through smoothly.
Jennifer C.
good and responsive workshop (Jin) the in-charge, has clear elaboration of the car's maintenance and its components wear-n-tear issues. Recommended workshop !
D
Battery, wipers, and AC filter replaced. The squeaky noise is gone and the AC smells fresh again. Great work, Steve!
Nick Luo W.
Brought my car for servicing, change of car battery and transmission oil. It was efficiently done and I could get back my car after 2 hours plus.
Law
Great service provided by Jin from 1 Car Service Workshop. Change of engine oil, gear oil, spark plugs and battery on my Audi A3. Tysm
Nigel Lee Shi Y.
Subaru battery replacement. Quick turnaround! Good job!
James L.
great service! Very prompt and explains well. Had a problem with my honda vezel battery, they did a thorough check to find the root cause. Thank you!
thashaini M.
I had my Volvo V40 serviced for a new auxiliary battery and timing belt change. Fast, efficient and to my satisfaction. The cost was very reasonable.
Niels de B.
Very good service! always do service & maintenance here for my Mercedes . Appreciate service advisor JIN. Tks!
Ming L.
ske2026g,car service,very good service and diagnosis was done well
Muhammad R.
sent my family car (Merc GLC Coupe 300 2022) in for 75k servicing at 1 Car servicing. brilliant job done by Jin, DX, Steve and the rest of the team!
Imran M.
Did a service for my cla180, Jin was very helpful and communication was efficient. Great experience overall.
Lou T.
Good, professional, fast servicing of my Mazda CX5. Highly recommend. Thumbs up to Steve for seeing the whole process through smoothly.
Jennifer C.
good and responsive workshop (Jin) the in-charge, has clear elaboration of the car's maintenance and its components wear-n-tear issues. Recommended workshop !
D
We test the auxiliary battery and the main battery to see how much charge they really hold, so you know the true condition and get an honest quote before any work.
We fit the correct battery for your car, usually a small AGM, and register it to the car where the model requires it so the charging system treats it as new.
An auxiliary battery that keeps failing is often a charging fault or a parasitic drain. We trace the real cause, not just swap the battery.
Most auxiliary batteries are replaced while you wait, with transparent pricing quoted before we start. Spread the cost with Atome, Grab or Shopee.
Many modern continental cars run two batteries, not one. The big main battery starts the engine. The auxiliary battery is the second, smaller one, and its job is to back up the car's electronics, keep the voltage steady every time start-stop shuts the engine off and restarts it, and hold up critical safety and comfort systems while the engine is not running.
It is usually a small AGM (Absorbent Glass Mat) battery, and like any battery it wears out, most often at about four to six years. When it does, the car cannot rely on it any more, and you get warning messages, start-stop that quietly stops working, and electrical glitches that come and go.
This is a different job from the main car battery replacement, and different again from a hybrid traction battery, which our hybrid battery repair page covers. If you are not sure which battery your car is warning you about, send us the model on WhatsApp and we will tell you.
On Mercedes-Benz this is the one people see most: an 'Auxiliary Battery Malfunction' message on the dash. It most often points to the small secondary battery weakening, so it can no longer steady the electrical system around the ECO start-stop and the electronics. But the message alone does not confirm the cause, so we test first: the main battery, the charging system or a wiring fault can trigger it too.
Many Mercedes from around 2005 onwards can carry this second battery, commonly the C-Class, E-Class, S-Class, CLS, GLC, GLE and GLS, and some smaller models too, though it depends on the exact model, year and variant, which we confirm before any work. Depending on the model it sits in the engine bay, or tucked in the passenger footwell behind the glovebox, and it is usually a small AGM battery. On some models, though, like certain W205 C-Class cars, the same message points to a voltage-converter module rather than a second battery, which is one more reason we diagnose before we replace anything.
Resetting the message only clears it for a while and fixes nothing, so the warning comes back. The proper fix is to test it, confirm whether it is the auxiliary battery, the main battery or the charging system, and replace the auxiliary battery only if that is the cause. We do this every week as part of our Mercedes workshop work, using XENTRY where the car needs the battery matched to it.
It is not only Mercedes. Plenty of continental cars carry a second battery, and each brand has its own name and quirks:
Hybrids and EVs also carry a separate low-voltage auxiliary battery, usually a 12V, apart from the big traction battery. When that small battery dies, the car often will not power up at all, even with a full traction battery.
An auxiliary battery rarely dies all at once. Catch these early and you avoid being stranded or chasing phantom electrical faults:
If any of this sounds familiar, send us your car model on WhatsApp and we will tell you what to check.
A car with an auxiliary battery warning is not always a battery problem, and it is not always a simple swap. Sometimes the auxiliary battery is fine and the real fault is the main battery, the alternator, a bad earth, or a parasitic drain quietly flattening things overnight. That is why we test first.
We test both batteries and the charging system, and show you the readings, before we quote you anything. If the auxiliary battery needs replacing, we fit the correct type, almost always a small AGM. On many continental cars the new battery then has to be registered, or coded, to the car so the battery management system knows it is new. Skip that and the car keeps charging it as if it were old, which shortens its life and can throw more warnings. We code it where the car needs it, using the same dealer-level tools we run across our brand work: XENTRY, ISTA, ODIS and VIDA.
If the battery keeps going flat for no obvious reason, the cause is usually a parasitic drain or a charging fault in the electronics, which we trace properly with an ECU and electrical diagnosis rather than just selling you another battery.
Small AGM auxiliary batteries do not last as long here as they do in cooler countries, and it is worth knowing why.
Constant heat under the bonnet speeds up the chemical wear inside the battery, so a battery that might last four to six years in a cooler climate often fades in three to four here. Short, stop-start city trips make it worse, because the charging system never gets enough time to fully top the battery back up. Cars that sit for days, and cars loaded with electronics and start-stop, drain the auxiliary battery faster still.
None of this means you did anything wrong. It just means the auxiliary battery is a wear item worth checking once it passes the three-year mark, before it leaves you with a dash full of warnings in a carpark.
1 Car Service replaces auxiliary batteries the right way. We test both batteries and the charging system first so you only replace what you need, fit the correct battery for your car, and code it where the car requires it. Most replacements are done at our Sin Ming workshop while you wait, with honest pricing quoted before we start, and you can spread the cost with Atome, Grab or Shopee. We do not do onsite or mobile battery replacement, because testing the charging system and coding the battery to your car needs our workshop tools.
WhatsApp us your car model and the warning you are seeing, and we will sort it out fast. It is all part of our full car repair and servicing under one roof, backed by a 4.9-star track record with Singapore drivers.
WhatsApp us your car model and the message on your dash. We test before we replace, quote before we start, and most auxiliary batteries are done while you wait. Spread the cost with Atome, Grab or Shopee.
WhatsApp a battery specialistEverything you need to know before you replace your car's auxiliary battery in Singapore:
It is a second, smaller battery, separate from the main battery that starts the engine. Its job is to back up the car's electronics, keep the voltage steady during start-stop, and hold up safety and comfort systems while the engine is not running. It is common on continental cars and is usually a small AGM battery.
It usually points to the small secondary battery in your Mercedes weakening, so it can no longer steady the electrical system around the ECO start-stop. Many Mercedes from around 2005 onwards carry this second battery, though it depends on the model and variant. The message alone does not confirm the cause, so we test both batteries and the charging system, and on some models it can even be a voltage-converter module rather than a battery.
Clearing the message does not fix or diagnose anything, so if the battery is worn the warning comes back. The message by itself does not tell you whether the fault is the auxiliary battery, the main battery or the charging system. The proper fix is to test first, confirm what is actually failing, and replace the auxiliary battery only if that is the cause.
It depends on the car. On many Mercedes it is in the engine bay, or tucked in the passenger footwell behind the glovebox. On other cars it can be in the boot or under a seat. We locate, test and replace it for you, so you do not have to go hunting.
No. On petrol and diesel cars the main battery starts the engine and is larger, while the auxiliary battery is the smaller second one that backs up the electronics and start-stop. Hybrids and EVs also run a separate low-voltage battery, usually a 12V, for the electronics, apart from the high-voltage traction system. If it is the main starting battery you need instead, our car battery replacement page covers that job.
Most often certain Mercedes-Benz, BMW, Audi, Volvo and Porsche models, usually the larger ones, though it depends on the exact model, year and variant, and not every start-stop car has one. Hybrids and EVs also have a separate low-voltage auxiliary battery, usually a 12V, that is not the traction battery. Send us your model or VIN and we will tell you what yours has.
Usually about four to six years, and often closer to three to four years in Singapore because of the heat and short trips. It is worth having it checked once it passes three years old, before it starts throwing warnings.
Where the car needs it, yes. Many Mercedes, BMW, Audi, Volkswagen and Volvo cars track the battery through a management system, so the new battery is registered to the car using dealer-level tools (XENTRY, ISTA, ODIS, VIDA). This makes the charging system treat it as new.
It depends on your car and the exact battery it takes. We test first, confirm whether it is the auxiliary battery, the main battery or a charging fault, and quote the exact price before any work begins, with no hard sell. You can spread the cost with Atome, Grab or Shopee.
We do not add a separate workmanship warranty on battery fitting. Any warranty on the battery itself comes from its maker and depends on the brand we fit, so ask us for the terms before you decide. What you get from us is an honest test so you only replace what you need, the correct battery for your car, and proper coding so it lasts as it should.
WhatsApp 1 Car Service about your auxiliary battery. We test the battery and the charging system, fit the correct battery for your car, and code it where the car needs it. Honest pricing quoted before any work begins, no hard sell. Spread the cost with Atome, Grab or Shopee.
Chat with a specialist on WhatsApp
Point your phone camera here to chat with us instantly.
Or open WhatsApp Web →Prefer to save our number?
